Mesa/Boogie MarkI Input Jack

[Kensel]

I do not know if aca corresponds this post. If it does not correspond to this section they excuse.

hello friends of the forum of Music Electronics. My excuses by my badly english, I speak Spanish. Mark I makes a mesa/boogie and has a doubt with respect to jack of input 1. I do not know that jack I must buy and like connecting it. I hope that somebody can help me. From already thank you very much.

http://www.tubefreak.com/mkirga_1.jpg

The original message:

hola amigos del foro de Hoffmanamps. Mis disculpas por mi mal english, yo hablo español.

Fabrique un mesa/boogie mark I y tengo una duda con respecto al jack de la entrada 1. No sé que jack tengo que comprar y como conectarlo. Espero que alguien pueda ayudarme. Desde ya muchas gracias

[Ray Ivers]

Kensel,

You need a Switchcraft 13A jack:

http://www.alliedelec.com/search/ProductDetail.asp?SKU=932-0051&source=froogle&detail=9320051

I've attached a schematic page as a thumbnail, which would not open in the preview.

Ray

[Shea]

Ray, are you sure it isn't a Switchcraft 113?

Shea

[Ray Ivers]

Shea,

Going by the print in the posted link, what he needs is a jack with an isolated 'make' circuit, to connect V1a's output to V1b's input (this is different from the original MK I Boogie prints I have, which require an isolated 'break' circuit). The 13A can do either of these plus shorting if need be, so I figured all bases were covered. It's also a standard Switchcraft metal/phenolic item, which I've found to be pretty durable (it may need to be chassis-isolated, I don't know).

The only 113 info I could find seems to indicate a standard stereo plug, non-switching (I haven't scoured the Web, so I could be mistaken). It's also one of the plastic-body Switchcrafts that I don't personally care for too much, but maybe Boogie uses those on the reissues - I haven't seen one yet.

Ray

[Shea]

Ray -

Check out this page from the Mouser catalog: http://www.mouser.com/catalog/626/853.pdf

Out of the circuit diagrams shown on the upper right, the 13A is circuit 3, and the 113 is circuit 9. I thought the #1 input jack on the schematic that Kensel linked to was more like circuit 9 than circuit 3.

I prefer the jacks with phenolic wafers too, but there aren't any listed there with "circuit 9."

Shea

[JerryP]

The Mesa MK1 uses a Switchcraft 13 on the high input jack. they are a pain to find, at least they were last time I needed one.
Jerry

[Ray Ivers]

Shea,

You're right - I stand corrected. The 13A is a 'transfer' jack, with the switch contacts working directly on the tip contact without any isolation. The 113 has a true isolated-make circuit, and is the one to use - thanks!

I've got two Switchcraft steel/phenolic jacks here with two isolated make/break contact sets (tip and ring) each, possibly pulled from a Music Man RD100 amp - I guess they've stopped making them, or maybe Mouser just doesn't carry them - probably not a real big seller. ;)

Ray